A spectacular banyan ('ovava in Tongan) growing out of a deep limestone sinkhole near the centre of the island, its aerial roots dropping fifteen metres down the cliff walls to reach the soil at the bottom. You descend into the sinkhole on a wooden ladder built against one wall — the descent itself is mildly hair-raising, the tree at the bottom unforgettable.
The 'ovava is sacred in Tongan tradition, said to be the home of forest spirits, and was traditionally tapu — forbidden to fell. This particular tree is one of the largest on the island and is signposted off the main road. Visit with the same guide who takes you into the national park; one local will arrange both.